To process materials of high-hardness, high-strength and high-viscosity, such as tungsten carbide, cerment, alloys of titanium base, nickel base of aluminum base, titanium alloys, cast iron with high content of chromium, and galvanized iron is as yet a problem in mechanical machining and electrical working or in other processes, processes, especially, when the workpieces to be processed are of very rough surfaces which require a rough machining to machine away a relative large quantity of materials from the workpieces. The conventional processes are in general with poor productivity, high cost and large energy consumption.
Moreover, the machines involved are easily worn out and there are requirements of expensive tools and abrasives. There appears also either a heavy labor or a low yield which has become a question to be solved in metal working industry.
CN 87106421 A discloses a combined process of electric discharge and mechanical grinding and the apparatus thereof for processing high-hardness metal materials. But it is still not satisfactory for its limited working efficiency and accuracy.